GPVI signaling defects in Jak2^Plt−/− platelets. (A) Jak2^Plt+/+ and Jak2^Plt−/− platelets were activated or not with CRP for 2 minutes at 37°C, as indicated. Platelet lysates corresponding to 2 µg protein were subjected to SDS-PAGE and probed for phosphotyrosine (pTyr), phosphorylated Lyn Tyr 396 (pLyn Tyr396), phosphorylated Syk Tyr525/526 (pSyk Tyr525/526), phosphorylated PLC-γ2 Tyr1217 (pPLC-γ2 Tyr1217), and β-actin as a loading control. Quantification of pLyn Tyr396 (B), pSyk Tyr525/526 (C), and pPLCγ2 Tyr1217 (D) in CRP-stimulated Jak2^Plt+/+ and Jak2^Plt−/− platelets. Results are the mean ± SD of 4 independent experiments and were compared with the control by 2-way ANOVA. **P < .01.